Correlation between antibiotic consumption and resistance of Gram-negative bacteria causing healthcare-associated infections at a university hospital in Taiwan from 2000 to 2009

Leveraging Large Data, Statistics, and Machine Learning to Predict the Emergence of Resistant E. coli Infections

Drug-resistant Gram-negative bacterial infections, on average, increase the length of stay (LOS) in U.S. hospitals by 5 days, translating to approximately $15,000 per patient. We used statistical and machine-learning models to explore the relationship between antibiotic usage and antibiotic resistance over time and to predict the clinical and financial costs associated with resistant E. coli infections. We acquired data on antibiotic utilization and the resistance/sensitivity of 4776 microbial cultures at a Kaiser Permanente facility from April 2013 to December 2019. The ARIMA (autoregressive integrated moving average), neural networks, and random forest time series algorithms were employed to model antibiotic resistance trends. The models' performance was evaluated using mean absolute error (MAE) and root mean squared error (RMSE). The best performing model was then used to predict antibiotic resistance rates for the year 2020. The ARIMA model with cefazolin, followed by the one with cephalexin, provided the lowest RMSE and MAE values without signs of overfitting across training and test datasets. The study showed that reducing cefazolin usage could decrease the rate of resistant E. coli infections. Although piperacillin/tazobactam did not perform as well as cefazolin in our time series models, it performed reasonably well and, due to its broad spectrum, might be a practical target for interventions in antimicrobial stewardship programs (ASPs), at least for this particular facility. While a more generalized model could be developed with data from multiple facilities, this study acts as a framework for ASP clinicians to adopt statistical and machine-learning approaches, using region-specific data to make effective interventions.

Lack of Association between Antimicrobial Consumption and Antimicrobial Resistance in a HIV Preexposure Prophylaxis Population: A Cross-Sectional Study

BACKGROUND

In antibiotic naïve populations, there is a strong association between the use of an antimicrobial and resistance to this antimicrobial. Less evidence is available as to whether this relationship is weakened in populations highly exposed to antimicrobials. Individuals taking HIV preexposure prophylaxis (PrEP) have a high intake of antimicrobials. We previously found that there was no difference in the prevalence of pheno- and genotypic antimicrobial resistance between two groups of PrEP clients who had, and had not, taken antimicrobials in the prior 6 months. Both groups did, however, have a higher prevalence of resistance than a sample of the general population.

METHODS

In the current study, we used zero-inflated negative binomial regression models to evaluate if there was an individual level association between the consumption of antimicrobials and 1. the minimum inhibitory susceptibilities of oral Neisseria subflava and 2. the abundance of antimicrobial resistance genes in the oropharynges of these individuals.

RESULTS

We found no evidence of an association between the consumption of antimicrobials and the minimum inhibitory susceptibilities of oral Neisseria subflava or the abundance of antimicrobial resistance genes in these individuals.

CONCLUSIONS

We conclude that in high-antimicrobial-consumption populations, the association between antimicrobial consumption and resistance may be attenuated. This conclusion would not apply to lower-consumption populations.

New lignan glycosides from Justicia secunda Vahl (Acanthaceae) with antimicrobial and antiparasitic properties

Three new lignan glucosides, namely, justisecundosides A (1), B (2a), and C (2b), were isolated from the whole plant of Justicia secunda together with seven known compounds (3-9). Their structures were established based on a comprehensive analysis of HR-ESI-MS, IR, UV, and CD, in conjunction with their 1D and 2D-NMR data. A putative biogenetic pathway of compounds 1-2a,b from coniferyl alcohol was proposed. In addition, the antimicrobialactivities of the extract, fractions, and some isolated compounds were assessed against multiresistant bacterial and fungal strains. Furthermore, the antiplasmodial, antileishmanial, and antitrypanosomal activities were assessed against the sensitive (3D7) and multidrug-resistant (Dd2) strains of P. falciparum, promastigote and bloodstream forms of L. donovani, and Trypanosoma brucei, respectively. Compound 4 exhibited moderate antibacterial activity against Staphylococcus aureus SA RN 46003 with a MIC value of 62.5 μg/mL. Besides, compound 6 demonstrated a very good activity against sensitive (IC50Pf3D7: 0.81 μg/mL) and multidrug-resistant (IC50PfDd2: 14.61 μg/mL) strains of P. falciparum while compound 4 displayed good antitrypanosomal activity (IC50: 1.19 μg/mL). Also, compound 1 was the most active on the promastigote form of L. donovani with an IC50 of 13.02 μg/mL.

Correlation between antibiotic use and resistance of gram-negative bacteria at a university hospital in Japan from 2013 to 2021: a study using the Japan Surveillance for Infection Prevention and Healthcare Epidemiology system

OBJECTIVES

The Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system aggregates information related to antimicrobial resistance (AMR) measures. We aimed to investigate the correlation between antibiotic use and AMR at a university hospital from 2013 to 2021 in a time series analysis using the J-SIPHE system. We also studied this correlation in each ward (inter-ward analysis).

METHODS

Data on antibiotic use and resistance rates were collected from the J-SIPHE system, except for the resistance rate in each ward, which was calculated from the source data prepared for this system.

RESULTS

Piperacillin/tazobactam use was positively correlated with piperacillin/tazobactam resistance in Escherichia coli and Klebsiella pneumoniae in the inter-ward analysis, and in Pseudomonas aeruginosa in both analyses. Carbapenem use was positively correlated with meropenem resistance in Enterobacter cloacae in the time series analysis and in P. aeruginosa in both analyses, and imipenem/cilastatin resistance in P. aeruginosa in inter-ward analysis. Quinolone use was positively correlated with levofloxacin resistance in E. coli in both analyses, and in K. pneumoniae in inter-ward analysis.

CONCLUSIONS

This is the first study to investigate the correlation between antibiotic use and AMR at a single hospital in time series and inter-ward analyses using the J-SIPHE system and data prepared for this system, suggesting that this system may be useful for promoting AMR measures.

Resistant Bacteria in Broiler Litter Used as Ruminant Feed: Effect of Biotic Treatment

The use of antimicrobial drugs and coccidiostats in poultry farming is widespread, with a significant proportion of these drugs being excreted and released into the environment. The residues of such drugs in poultry litter (PL) can result in the development of antibiotic-resistant bacteria. The impact of different biotic treatments (aerobic, anaerobic, and stacking) on broiler litter (BL) before its use as animal feed has not been studied extensively, nor have the differences between antimicrobial-dependent and independent broiler farms been investigated. This study aimed to determine the resistant bacteria in BL used as ruminant feed before and after litter treatment. The results show that the most resistant bacteria before BL treatment were the Enterococcus species. This study also found that the quantity of amoxicillin-resistant Enterococcus detected in samples from antimicrobial-dependent farms was significantly higher than in those from antimicrobial-independent farms. Additionally, 14% of bacteria were multi-resistant to tetracycline, sulfafurazole, and erythromycin in antimicrobial-independent farm litters, significantly lower than those measured in antimicrobial-dependent broiler farm litter. This study highlights the importance of better understanding, regulating, managing, and using animal waste appropriately to reduce the number of antibiotic-resistant bacteria and minimize the use of antimicrobials that carry high risks for animals, humans, and the environment.

Correlation between antibiotic consumption and resistance of Pseudomonas aeruginosa in a teaching hospital implementing an antimicrobial stewardship program: A longitudinal observational study

BACKGROUND/PURPOSE

The rapid emergence of Pseudomonas aeruginosa resistance made selecting antibiotics more challenge. Antimicrobial stewardship programs (ASPs) are urging to implant to control the P. aeruginosa resistance. The purpose of this study is to evaluate the relationship between antimicrobial consumption and P. aeruginosa resistance, the impact of ASPs implemented during the 14-year study period.

METHODS

A total 14,852 P. aeruginosa isolates were included in our study. The resistant rate and antimicrobial consumption were investigated every six months. Linear regression analysis was conducted to examine the trends in antibiotics consumption and antimicrobial resistance over time. The relationship between P. aeruginosa resistance and antimicrobial consumption were using Pearson correlation coefficient to analysis. The trend of resistance before and after ASPs implanted is evaluated by segment regression analysis.

RESULTS

P. aeruginosa resistance to ceftazidime, gentamicin, amikacin, ciprofloxacin and levofloxacin significantly decreased during the study period; piperacillin/tazobactam (PTZ), cefepime, imipenem/cilastatin and meropenem remained stable. The P. aeruginosa resistance to ciprofloxacin and levofloxacin increasing initial then decreased after strictly controlled the use of levofloxacin since 2007. As the first choice antibiotic to treat P. aeruginosa, the consumption and resistance to PTZ increase yearly and resistance became stable since extended-infusion therapy policy implant in 2009.

CONCLUSION

Our ASP intervention strategy, which included extended infusion of PTZ and restrict use of levofloxacin, may be used to control antimicrobial resistance of P. aeruginosa in medical practice.

Correlation between antibiotic use and antibiotic resistance: A multicenter study using the Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system in Hokkaido, Japan

BACKGROUND

The Japan Surveillance for Infection Prevention and Healthcare Epidemiology (J-SIPHE) system aggregates information related to antimicrobial resistance (AMR) measures in participating medical institutions nationwide and is intended to be used for promotion of AMR measures in participating facilities and their communities. This multicenter study aimed to determine the usefulness of the J-SIPHE system for evaluating the correlation between antibiotic use and antibiotic resistance in Hokkaido, Japan.

METHODS

Data on antibiotic use and detection rate of major resistant Gram-negative bacteria at 19 hospitals in 2020 were collected from the J-SIPHE system, and data correlations were analyzed using JMP Pro.

RESULTS

The detection rate of carbapenem-resistant Pseudomonas aeruginosa was significantly positively correlated with carbapenem use (Spearman's ρ = 0.551; P = .015). There were significant positive correlations between the detection rate of fluoroquinolone-resistant Escherichia coli and the use of piperacillin/tazobactam, carbapenems, and quinolones [ρ = 0.518 (P = .023), ρ = 0.76 (P < .001), and ρ = 0.502 (P = .029), respectively].

CONCLUSIONS

This is the first multicenter study to investigate the correlation between antibiotic use and antibiotic resistance using the J-SIPHE system. The results suggest that using this system may be beneficial for promoting AMR measures.

Associations of antimicrobial use with antimicrobial susceptibility at the calf level in bacteria isolated from the respiratory and digestive tracts of veal calves before slaughter

Objectives

Antimicrobial drugs are frequently administered in veal calves, but investigations on associations with antimicrobial susceptibility of bacteria are scarce and convey partly contradictory findings. The aim of this study was to investigate associations of antimicrobial use (AMU) during the fattening period with antimicrobial susceptibility shortly before slaughter.

Methods

Detailed treatment data of 1905 veal calves from 38 farms were collected prospectively during monthly farm visits for 1 year (n = 1864 treatments, n = 535 visits); 1582 Escherichia coli, 1059 Pasteurella multocida and 315 Mannheimia haemolytica were isolated from rectal and nasopharyngeal swabs collected before slaughter and subjected to antimicrobial susceptibility testing by microdilution. Associations of antimicrobial treatments with resistant isolates were investigated at the calf level.

Results

Associations of AMU with antimicrobial resistance were observed using generalized linear models. For E. coli, the odds of being resistant were increased with increased AMU (OR 1.36 when number of treatments >1, P = 0.066). Use of tetracyclines was associated with resistance to tetracycline (OR 1.86, P < 0.001) and use of penicillins was associated with resistance to ampicillin (OR 1.66, P = 0.014). No significant associations were observed for P. multocida (use of aminoglycosides: OR 3.66 for resistance to spectinomycin, P = 0.074). For M. haemolytica, the odds of being resistant were increased with increased AMU (OR 4.63, P < 0.001), and use of tetracyclines was associated with resistance to tetracycline (OR 6.49, P < 0.001).

Conclusions

Occurrence of resistant bacteria shortly before slaughter was associated with AMU in veal calves. Prudent and appropriate use may contribute to limit the selection of resistant bacteria on veal farms.

High antimicrobial activity of lactoferricin-expressing Bacillus subtilis strains

The lactoferricin expressed in Bacillus subtilis is relatively low in yield, making it hard to apply in industrial settings. We constructed a six tandem repeat of lactoferricin cDNA driven by promoter PtrnQ. After transformation, two transformants P245 and P263 possessing a stable inheritance of plasmid and high expression of lactoferricin were selected. The bactericidal activities, 1 μl of aliquot of a total 5.5 ml of solution extracted from 5 ml of cultured P245 and P263, were equivalent to the efficacy of 238.25 and 322.7 ng of Ampicillin against Escherichia coli, respectively, and 366.4 and 452.52 ng of Ampicillin against Staphylococcus epidermidis respectively. These extracts were able to kill an Ampicillin‐resistant E. coli strain. The bactericidal activities of P245 and P263 equivalent to the efficacy of Tetracycline against Vibrio parahaemolyticus and V. alginolyticus were also determined. Moreover, the bactericidal activities of P245 and P263 were 168.04 and 249.94 ng of Ampicillin against Edwardsiella tarda, respectively, and 219.7 and 252.43 ng of Tetracycline against Streptococcus iniae respectively. Interestingly, the survival rate of E. tarda‐infected tilapia fry fed the P263 extract displayed a significantly greater than that of the fry‐fed control strain. Collectively, these B. subtilis transgenic strains are highly promising for use in animal husbandry during a disease outbreak.

Antimicrobial Effects of Novel H2O2-Ag+ Complex on Membrane Damage to Staphylococcus aureus, Escherichia coli O157:H7, and Salmonella Typhimurium

ABSTRACT

Diseases caused by harmful microorganisms pose a serious threat to human health. Safe and environmentally friendly disinfectants are, therefore, essential in preventing and controlling such pathogens. This study aimed to investigate the antimicrobial activity and mechanism of a novel hydrogen peroxide and silver (H2O2-Ag+) complex (HSC) in combatting Staphylococcus aureus ATCC 29213, Escherichia coli O157:H7 NCTC 12900, and Salmonella Typhimurium SL 1344. The MICs and MBCs against S. aureus were found to be 0.014% H2O2-3.125 mg/L Ag+, and for both E. coli O157:H7 and Salmonella Typhimurium they were 0.028% H2O2-6.25 mg/L Ag+. Results of the time-kill trial suggest that HSC could inhibit the growth of the tested bacteria, because 99.9% of viable cells were killed following treatment at 1 MIC for 3 h. The mechanism of antibacterial action of HSC was found to include the disruption of the bacterial cell membrane, followed by reduction of intracellular ATP concentration and inhibition of the activity of antioxidases, superoxide dismutase, and catalase. The enhanced bactericidal effect of hydrogen peroxide combined with silver indicates a potential for its application in environmental disinfection, particularly in the food industry.

HIGHLIGHTS

Trends of Antibiotic Use and Expenditure After an Intensified Antimicrobial Stewardship Policy at a 2,200-Bed Teaching Hospital in China

Objective: This study aimed to evaluate the effects of intensified Chinese special rectification activity on clinical antibiotic use (CSRA) policy on a tertiary-care teaching hospital. Methods: A 48-month longitudinal dataset involving inpatients, outpatients, and emergency patients were collected. Study period included pre-intervention stage (adopting soft measures like systemic training) and post-intervention stage (applying antibiotic control system to intensify CSRA policy). Antibiotic use was evaluated by antibiotic use rate (AUR) or antibiotic use density (AUD). Economic indicator was evaluated by antibiotic cost in prescription or antibiotic expenditure in hospitalization. Data was analyzed by interrupted time series (ITS) analysis. Results: The medical quality indicators remained stable or improved during the study period. AUR of inpatients (AURI) declined 0.553% per month (P = 0.025) before the intervention and declined 0.354% per month (P = 0.471) after the intensified CSRA policy was implemented. AUD, expressed as defined daily doses per 100 patients per day (DDDs/100PD), decreased by 1.102 DDDs/100PD per month (P = 0.021) before and decreased by 0.597 DDDs/100PD per month (P = 0.323) thereafter. The ratio of antibiotic expenditure to medication expenditure (AE/ME) decreased by 0.510% per month (P = 0.000) before and fell by 0.096% (P = 0.000) per month thereafter. AE per patient decreased by 25.309 yuan per month (P = 0.002) before and decreased by 7.987 yuan per month (P = 0.053) thereafter. AUR of outpatient (AURO) decreased by 0.065% per month before (P = 0.550) and decreased by 0.066% per month (P = 0.994) thereafter. The ratio of antibiotic cost to prescription cost in outpatient (ACO/PCO) decreased by 0.182% per month (P = 0.506) before and decreased by 0.216% per month (P = 0.906) thereafter. AUR of emergency patient (AURE) decreased by 0.400% per month (P = 0.044) before and decreased by 0.092% per month (P = 0.164) thereafter. The ratio of antibiotic cost to prescription cost in emergency patient (ACE/PCE) decreased by 0.616% per month (P < 0.001) before and decreased by 0.151% per month (P < 0.001) thereafter. Conclusions: Implementation of CSRA policy was associated with declining antibiotic use and antibiotic expenditure in inpatients, outpatients, and emergency patients. However, it is also important to note that the declining trend of antibiotic consumption slowed due to the limited capacity for decline in the later stages of CSRA intervention.

Temporal association between antibiotic use and resistance in Gram-negative bacteria

The β-lactam/lactamase inhibitors (BLBLIs) combination drugs are considered an effective alternative to carbapenems. However, there is a growing concern that the increased use of BLBLIs may lead to increased resistance. This study determined the temporal association between the consumption of BLBLI and the antimicrobial resistance in Gram-negative bacteria. In this retrospective study, electronic data on the Gram-negative bacterial isolates, including A. baumannii, P. aeruginosa, E. coli, and K. pneumoniae from in-patients and susceptibility testing results were retrieved from the medical records of the clinical laboratory. A linear regression and cross-correlation analysis were performed on the acquired data. Increasing trends (p<0.05) in the consumption of BIBLI and carbapenem with a median use of 27.68 and 34.46 DDD/1000 PD per quarter were observed, respectively. A decreased trend (p=0.023) in the consumption of fluoroquinolones with a median use of 29.13 DDD/1000 PD per quarter was observed. The resistance rate of K. pneumoniae was synchronized with the BIBLI and carbapenem consumptions with a correlation coefficient of 0.893 (p=0.012) and 0.951 (p=0.016), respectively. The cross-correlation analysis against the consumption of BIBLI and meropenem resistant K. pneumoniae was peaked at 0-quarter lag (r=951, p=0.016). There was an increasing trend in the consumption of BLBLI and carbapenems. The increasing trend in the rates of resistance to piperacillin/tazobactam, in line with the increasing consumption of BLBLI, suggests that BLBLI has to be used with caution and cannot be directly considered as a long-term alternative to carbapenems.

Potent antifungal agents and use of nanocarriers to improve delivery to the infected site: A systematic review

There are four major classes of antifungals with the predominant mechanism of action being targeting of cell wall or cell membrane. As in other drugs, low solubility of these compounds has led to low bioavailability in target tissues. Enhanced drug dosages have effects such as toxicity, drug-drug interactions, and increased drug resistance by fungi. This article reviews the current state-of-the-art of antifungals, structure, mechanism of action, other usages, and toxic side effects. The emergence of nanoformulations to transport and uniformly release cargo at the target site is a boon in antifungal treatment. The article details research that lead to the development of nanoformulations of antifungals and potential advantages and avoidance of the lacunae characterizing conventional drugs. A range of nanoformulations based on liposomes, polymers are in various stages of research and their potential advantages have been brought out. It could be observed that under similar dosages, test models, and duration, nanoformulations provided enhanced activity, reduced toxicity, higher uptake and higher immunostimulatory effects. In most instances, the mechanism of antifungal activity of nanoformulations was similar to that of regular antifungal. There are possibilities of coupling multiple antifungals on the same nano-platform. Increased activity coupled with multiple mechanisms of action presents for nanoformulations a tremendous opportunity to overcome antifungal resistance. In the years to come, robust methods for the preparation of nanoformulations taking into account the repeatability and reproducibility in action, furthering the studies on nanoformulation toxicity and studies of human models are required before extensive use of nanoformulations as a prescribed drug.

Extended-Spectrum β-Lactamase and Carbapenemase Producing Gram-Negative Bacilli Infections Among Patients in Intensive Care Units of Felegehiwot Referral Hospital: A Prospective Cross-Sectional Study

Background

Owing to the specific risk profile of its residents, intensive care units (ICUs) are the best place for selection pressure and the epicenter for resistance development and dissemination. Infections with β-lactamase releasing Gram-negative bacilli (GNB) at ICUs are an emerging global threat. This study dogged the magnitude of extended-spectrum β-lactamase (ESBL) and carbapenemase releasing Gram-negative bacilli infections and associated factors among patients in the ICUs of Felegehiwot Referral Hospital, Ethiopia.

Methods

A cross-sectional study was done through February to June 2020. Wound swabs, urine, blood and sputum samples were collected from patients in the ICUs symptomatic for infections while excluding those under coma and shock. Bacterial species were verified using standard microbiological methods. Carbapenemase and ESBL production were identified using modified carbapenem inactivation and combined disk diffusion methods, respectively. Multivariable analysis was calculated for factors associated with ESBL production. P-value < 0.05 was taken as cut-off for statistical significance.

Results

Out of 270 patients in the ICU, 67 (24.8%) and 14 (5.2%) had infections with ESBL and carbapenemase releasing GNB, respectively. The most frequent ESBL producing isolates were P. aeruginosa (100%), E. cloacae (100%), K. pneumoniae (82.8%) and E. coli (64%). The predominant carbapenemase producer isolates were K. pneumoniae (27.6%) and E. cloacae (33.3%). Overall, 77 (81.1%) of species were multi-drug resistant. All GNB species were 100% resistant to tetracycline and ampicillin. They are also resistant to cefuroxime, ceftazidime, sulfamethoxazole-trimethoprim and cefotaxime. Prior hospitalization (AOR = 5.5, CI = 2.63-11.46), support with medical care devices (AOR = 23.7, CI = 4.6-12) and arterial intravenous catheterization (AOR = 2.7, CI = 1.3-5.3) had significant association with β-lactamase producing GNB infection.

Conclusion

Infection with ESBL and carbapenemase producing Gram-negative bacilli linked with an alarming degree of multi-drug resistant isolates is a major healthcare threat among patients in ICUs. Hence, strict adherence to infection prevention practices and wise use of antibiotics are recommended to slow the spread of antimicrobial resistance.

Implementation of Antibiotic Stewardship in a University Hospital Setting

The article describes activities of an antibiotic center at a university hospital in the Czech Republic and presents the results of antibiotic stewardship program implementation over a period of 10 years. It provides data on the development of resistance of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus to selected antibiotic agents as well as consumption data for various antibiotic classes. The genetic basis of resistance to beta-lactam antibiotics and its clonal spread were also assessed. The study showed significant correlations between aminoglycoside consumption and resistance of Escherichia coli and Klebsiella pneumoniae to gentamicin (r = 0.712, r = 0.869), fluoroquinolone consumption and resistance of Klebsiella pneumoniae to ciprofloxacin (r = 0.896), aminoglycoside consumption and resistance of Pseudomonas aeruginosa to amikacin (r = 0.716), as well as carbapenem consumption and resistance of Pseudomonas aeruginosa to meropenem (r = 0.855). Genotyping of ESBL- positive isolates of Klebsiella pneumoniae and Escherichia coli showed a predominance of CTX-M-type; in AmpC-positive strains, DHA, EBC and CIT enzymes prevailed. Of 19 meropenem-resistant strains of Klebsiella pneumoniae, two were identified as NDM-positive. Clonal spread of these strains was not detected. The results suggest that comprehensive antibiotic stewardship implementation in a healthcare facility may help to maintain the effectiveness of antibiotics against bacterial pathogens. Particularly beneficial is the work of clinical microbiologists who, among other things, approve administration of antibiotics to patients with bacterial infections and directly participate in their antibiotic therapy.

Metagenomic insights into the antibiotic resistome of mangrove sediments and their association to socioeconomic status

Mangrove sediments are prone to anthropogenic activities that could enrich antibiotics resistance genes (ARGs). The emergence and dissemination of ARGs are of serious concern to public health worldwide. Therefore, a comprehensive resistome analysis of global mangrove sediment is of paramount importance. In this study, we have implemented a deep machine learning approach to analyze the resistome of mangrove sediments from Brazil, China, Saudi Arabia, India, and Malaysia. Geography (R_ANOSIM = 39.26%; p < 0.005) as well as human intervention (R_ANOSIM = 16.92%; p < 0.005) influenced the ARG diversity. ARG diversity was also inversely correlated to the human development index (HDI) of the host country (R = -0.53; p < 0.05) rather than antibiotics consumption (p > 0.05). Several genes including multidrug efflux pumps were significantly (p < 0.05) enriched in the sites with human intervention. Resistome was consistently dominated by rpoB2 (19.26 ± 0.01%), multidrug ABC transporter (10.40 ± 0.23%), macB (8.84 ± 0.36n%), tetA (4.13 ± 0.35%), mexF (3.26 ± 0.19%), CpxR (2.93 ± 0.2%), bcrA (2.38 ± 0.24%), acrB (2.37 ± 0.18%), mexW (2.19 ± 0.17%), and vanR (1.99 ± 0.11%). Besides, mobile ARGs such as vanA, tet(48), mcr, and tetX were also detected in the mangrove sediments. Comparative analysis against terrestrial and ocean resistomes showed that the ocean ecosystem harbored the lowest ARG diversity (Chao1 = 71.12) followed by mangroves (Chao1 = 258.07) and terrestrial ecosystem (Chao1 = 294.07). ARG subtypes such as abeS and qacG were detected exclusively in ocean datasets. Likewise, rpoB2, multidrug ABC transporter, and macB, detected in mangrove and terrestrial datasets, were not detected in the ocean datasets. This study shows that the socioeconomic factors strongly determine the antibiotic resistome in the mangrove. Direct anthropogenic intervention in the mangrove environment also enriches antibiotic resistome.

A decade of antimicrobial resistance research in social science fields: a scientometric review

Background

Though social sciences are expectedly instrumental in combating antimicrobial resistance (AMR), their research on AMR has been historically lacking.

Objectives

This study aims to understand the current academic literature on AMR within the social science field by investigating international contributions, emerging topics, influential articles, and prominent outlets, to identify research gaps and future directions.

Methods

Bibliometric data of 787 peer-reviewed journal articles published in the period of 2010 to 2019 were extracted from the Social Science Citation Index in the Web of Science database. Bibliographic networks of the extracted articles were examined.

Results

Social science research on AMR has grown rapidly in the past 5 years. While western developed countries contributed the most to the field in the past decade, research within developing regions such as Asia and Africa have increased in the last 2 years. Social sciences have been contributing to AMR research in several different domains from surveillance and risk assessment of AMR, to promotions of appropriate use of antimicrobials in primary care and clinical settings. Though the idea of one health has been incorporated into research on AMR within the medical and microbial science fields, it has not been well recognized by social sciences.

Conclusion

Social science research on AMR is a new, while rapidly developing, research area that requires continued and intense global efforts from an interdisciplinary and one health approach. Research on social issues surrounding AMR transmissions between human, animal, and environments should be emphasized in the future.

Increased financial burdens and lengths of stay in patients with healthcare-associated infections due to multidrug-resistant bacteria in intensive care units: A propensity-matched case-control study

Background and objectives

Incidence rates of healthcare-associated infections (HAIs) depend upon infection control policy and practices, and the effectiveness of the implementation of antibiotic stewardship. Amongst intensive care unit (ICU) patients with HAIs, a substantial number of pathogens were reported to be multidrug-resistant bacteria (MDRB). However, impacts of ICU HAIs due to MDRB (MDRB-HAIs) remain understudied. Our study aimed to evaluate the negative impacts of MRDB-HAIs versus HAIs due to non-MDRB (non-MRDB-HAIs).

Methods

Among 60,317 adult patients admitted at ICUs of a 2680-bed medical centre in Taiwan between January 2010 and December 2017, 279 pairs of propensity-score matched MRDB-HAI and non-MRDB-HAI were analyzed.

Principal findings

Between the MDRB-HAI group and the non-MDRB-HAI group, significant differences were found in overall hospital costs, costs of medical and nursing services, medication, and rooms/beds, and in ICU length-of-stay (LOS). As compared with the non-MDRB-HAI group, the mean of the overall hospital costs of patients in the MDRB-HAI group was increased by 26%; for categorized expenditures, the mean of costs of medical and nursing services of patients in the MDRB-HAI group was increased by 8%, of medication by 26.9%, of rooms/beds by 10.3%. The mean ICU LOS in the MDRB-HAI group was increased by 13%. Mortality rates in both groups did not significantly differ.

Conclusions

These data clearly demonstrate more negative impacts of MDRB-HAIs in ICUs. The quantified financial burdens will be helpful for hospital/government policymakers in allocating resources to mitigate MDRB-HAIs in ICUs; in case of need for clarification/verification of the medico-economic burdens of MDRB-HAIs in different healthcare systems, this study provides a model to facilitate the evaluations.

Five-year surveillance and correlation of antibiotic consumption and resistance of Gram-negative bacteria at an intensive care unit in Serbia

A surveillance study was performed in an intensive care unit in the largest tertiary health care center in Vojvodina, Serbia from 2014 to 2018. Antibiotic prescription data were collated in the WHO anatomical therapeutic chemical (ATC)/defined daily dose (DDD) format, while antibiotic resistance was expressed as incidence density adjusted for total inpatient-days. Individual trends were determined by linear regression, while possible associations between antibiotic prescription and resistance were evaluated using cross-correlation analysis. An overall decrease in antibiotic utilization was observed. The prescription rates of piperacillin-tazobactam increased significantly, while consumption of 3rd and 4th generation cephalosporins and fluoroquinolones decreased. There were rising incidence densities of doripenem resistant Acinetobacter spp., piperacillin-tazobactam resistant Pseudomonas aeruginosa and carbapenem and colistin resistant Klebsiella pneumoniae. These results can serve as a basis for the development of antimicrobial stewardship strategies in the current setting.

Ten-year resistance trends in pathogens causing healthcare-associated infections; reflection of infection control interventions at a multi-hospital healthcare system in Saudi Arabia, 2007-2016

Background

Studying temporal changes in resistant pathogens causing healthcare-associated infections (HAIs) is crucial in improving local antimicrobial and infection control practices. The objective was to describe ten-year trends of resistance in pathogens causing HAIs in a tertiary care setting in Saudi Arabia and to compare such trends with those of US National Health Surveillance Network (NHSN).

Methods

Pooled analysis of surveillance data that were prospectively collected between 2007 and 2016 in four hospitals of Ministry of National Guard Health Affairs. Definitions and methodology of HAIs and antimicrobial resistance were based on NHSN. Consecutive NHSN reports were used for comparisons.

Results

A total 1544 pathogens causing 1531 HAI events were included. Gram negative pathogens (GNP) were responsible for 63% of HAIs, with a significant increasing trend in Klebsiella spp. and a decreasing trend in Acinetobacter. Methicillin-resistant Staphylococcus aureus (27.0%) was consistently less frequent than NHSN. Vancomycin-resistant Enterococci (VRE, 20.3%) were more than doubled during the study, closing the gap with NHSN. Carbapenem resistance was highest with Acinetobacter (68.3%) and Pseudomonas (36.8%). Increasing trends of carbapenem resistance were highest in Pseudomonas and Enterobacteriaceae, closing initial gaps with NHSN. With the exception of Klebsiella and Enterobacter, multidrug-resistant (MDR) GNPs were generally decreasing, mainly due to the decreasing resistance towards cephalosporins, fluoroquinolones, and aminoglycosides.

Conclusion

The findings showed increasing trends of carbapenem resistance and VRE, which may reflect heavy use of carbapenems and vancomycin. These findings may highlight the need for effective antimicrobial stewardship programs, including monitoring and feedback on antimicrobial use and resistance.

Measuring Appropriate Antibiotic Prescribing in Acute Hospitals: Development of a National Audit Tool Through a Delphi Consensus

This study developed a patient-level audit tool to assess the appropriateness of antibiotic prescribing in acute National Health Service (NHS) hospitals in the UK. A modified Delphi process was used to evaluate variables identified from published literature that could be used to support an assessment of appropriateness of antibiotic use. At a national workshop, 22 infection experts reached a consensus to define appropriate prescribing and agree upon an initial draft audit tool. Following this, a national multidisciplinary panel of 19 infection experts, of whom only one was part of the workshop, was convened to evaluate and validate variables using questionnaires to confirm the relevance of each variable in assessing appropriate prescribing. The initial evidence synthesis of published literature identified 25 variables that could be used to support an assessment of appropriateness of antibiotic use. All the panel members reviewed the variables for the first round of the Delphi; the panel accepted 23 out of 25 variables. Following review by the project team, one of the two rejected variables was rephrased, and the second neutral variable was re-scored. The panel accepted both these variables in round two with a 68% response rate. Accepted variables were used to develop an audit tool to determine the extent of appropriateness of antibiotic prescribing at the individual patient level in acute NHS hospitals through infection expert consensus based on the results of a Delphi process.

Relationship Between Antimicrobial Prescribing and Antimicrobial Resistance Among UTI Patients at Buraidah Central Hospital, Saudi Arabia

Introduction:

Most of the decisions regarding diagnosis and treatment are based on laboratory test results. Urinary tract infections (UTIs) are among the most common infections in humans. The changing antimicrobial sensitivity in UTI requires appropriate antibiotics. Antimicrobial resistance is an emerging problem in the Kingdom of Saudi Arabia where the complete reversal of antimicrobial resistance is difficult due to irrational use of antibiotics.

Objectives:

This study aimed to determine the most common bacterial agents causing UTI in different seasons among patients who were admitted to Buraidah Central Hospital (BCH), Saudi Arabia. The study also evaluated the link between prescribing and resistance toward antimicrobials.

Materials and Methods:

A 6-month retrospective study was conducted among adult patients who were admitted to the inpatient department at BCH. A total of 379 files were collected from microbiological laboratory for inpatients.

Results:

Most UTI-causing bacteria prevailed in the same season. Of 15 bacterial strains, 12 were significantly correlated with 20 (of a total of 40) antibiotics that were used. Most bacteria were gram-negative. Gram-negative bacilli including Escherichia coli, Klebsiella spp., and Pseudomonadaceae and gram-positive Enterococcus faecalis were most frequently causing UTIs.

Conclusion:

Overall prevalence of antibiotic resistance was negative in bacterial isolates. However, the relationship between antimicrobial prescribing and antimicrobial resistance was significantly negative among UTI patients in BCH, Saudi Arabia.

Trends and correlation between antibiotic usage and resistance pattern among hospitalized patients at university hospitals in Korea, 2004 to 2012: A nationwide multicenter study

The aim of this study was to evaluate the changing pattern of antibiotic usage and antimicrobial resistance of bacterial pathogens among hospitalized patients in Korea. We simultaneously investigated the correlation between antimicrobial resistance and antibiotic consumption.Data on total antibiotic prescriptions, patient days, and antimicrobial sensitivity tests among inpatients from 6 university hospitals in Korea in 2004, 2008, and 2012 were collected. The consumption of each antibiotic class was converted to defined daily dose/1000 patient-days by using the anatomical therapeutic chemical classification system by the World Health Organization. We defined third-generation cephalosporins (3rd CEPs), fourth-generation cephalosporins, beta-lactam/beta-lactamase inhibitors, and fluoroquinolones (FQs) as broad-spectrum antibiotics and carbapenems, tigecycline, glycopeptides, oxazolidinone, and polymyxin as antibiotics against multidrug-resistant (MDR) pathogens.A 15.1% decrease in total antibiotic consumption was observed in 2012 compared to that observed in 2004. In contrast, a 10.2% and 70.7% increase in broad-spectrum antibiotics and antibiotics against MDR pathogens were observed, respectively, in the same period. The resistance rate of Escherichia coli to 3rd CEPs (17.6% in 2004, 21.7% in 2008, and 33.8% in 2012, P <.001) and ciprofloxacin (37.5% in 2004, 38.7% in 2008, and 46.6% in 2012, P = .001) demonstrated a significantly increasing trend. Similarly, the resistance rate of Klebsiella pneumoniae to 3rd CEPs (34.3% in 2004, 33.7% in 2008, and 44.5% in 2012, P <.001) gradually increased. Resistance of Acinetobacter baumanii and Pseudomonas aeruginosa to imipenem significantly increased throughout the study period (A baumanii: 8.9% in 2004, 40.8% in 2008, and 65.3% in 2012, P <.001; P aeruginosa: 25.1% in 2004, 31.5% in 2008, and 29.7% in 2008, P = .050).The consumption of carbapenems and FQs demonstrated significant positive correlation for resistance of E coli or K pneumoniae to 3rd CEPs as well as E coli or K pneumoniae to ciprofloxacin. Increasing resistance of A baumanii to ciprofloxacin was significantly correlated with increasing consumption of FQs; increasing resistance of A baumanii to imipenem was significantly correlated with increasing consumption of carbapenems.In conclusion, overall antimicrobial resistance increased and consumption of broad-spectrum antibiotics and antibiotics against MDR pathogens subsequently increased in Korean hospitals.

Synthesis of a Series of Chalcones and Related Flavones and Evaluation of their Antibacterial and Antifungal Activities

Background:

A series of chalcones and flavones were synthesized from 2’-hydroxyacetophenone and substituted aromatic aldehydes via Simmons-Schmidt condensation followed by oxidative cyclization.

Methods:

Characterization of the obtained structures was established on the basis of their spectroscopic data. The synthesized compounds were screened for their antimicrobial activities against five bacterial strains (Citrobacter freundii, Staphylococcus aureus, Listeria monocytogenes, Salmonella braenderup, Escherichia coli.) and two fungal strains (Candida albicans, Candida krusei).

Results:

The in vitro bioassay results indicated that some target compounds displayed moderate (4d, 4e) to high (4a) antifungal activity against the pathogenic fungi C. albicans and C. krusei.

Conclusion:

For the antibacterial activity, only products 3d and 4d showed a weak antibacterial activity. These compounds can lead to the design of new drugs with specific antifungal activity.

Antimicrobial activities of saponins from Melanthera elliptica and their synergistic effects with antibiotics against pathogenic phenotypes

BACKGROUND

Resistance of bacteria and fungi to antibiotics is one of the biggest problems that faces public health. The present work was designated to evaluate the antimicrobial activities of saponins from Melanthera elliptica and their synergistic effects with standard antibiotics against pathogenic phenotypes. The plant extract was prepared by maceration in methanol. The methanol extract was partitioned into ethyl acetate and n-butanol extracts. Column chromatography of the n-butanol extract followed by purification of different fractions led to the isolation of four saponins. Their structures were elucidated on the basis of spectra analysis, and by comparison with those from the literature. The antimicrobial activities of the extracts/compounds alone and their combinations with tetracycline and fluconazole were evaluated using the broth microdilution method through the determination of minimum inhibitory concentration (MIC) and minimum microbicidal concentration.

RESULTS

Four compounds: 3-O-β-D-glucuronopyranosyl-oleanolic acid (1), 3-O-β-D-glucuronopyranosyloleanolic acid 28-O-β-D-glucopyranosyl ester (2), 3-O-β-D-glucopyranosyl(1 → 2)-β-D-glucuronopyranosyl oleanolic acid (3) and 3-O-β-D-glucopyranosyl(1 → 2)-β-D-glucuronopyranosyl oleanolic acid 28-O-β-D-glucopyranosyl ester (4) were isolated. Compounds 1, 2 and 3 showed the largest antibacterial activities (MIC = 8-128 μg/mL) whereas compound 4 displayed the highest antifungal activities (MIC = 8-16 μg/mL). The antibacterial activities of compounds 1 and 2 (MIC = 16-32 μg/mL) against multi-drug-resistant Escherichia coli S2 (1) and Shigella flexneri SDINT are equal to those of vancomycin (MIC = 16-32 μg/mL) used as reference antibiotic.

CONCLUSIONS

The present study showed significant antimicrobial activity of compounds 1, 2, 3 and 4 against the tested microorganisms. The saponins act in synergy with the tested standard antibiotics. This synergy could lead to new options for the treatment of infectious diseases and emerging drug resistance.

Intra-hospital differences in antibiotic use correlate with antimicrobial resistance rate in Escherichia coli and Klebsiella pneumoniae: a retrospective observational study

Background

Monitoring antimicrobial use and resistance in hospitals are important tools of antimicrobial stewardship programs. We aimed to determine the association between the use of frequently prescribed antibiotics and the corresponding resistance rates in Escherichia coli and Klebsiella pneumoniae among the clinical departments of a tertiary care hospital.

Methods

We performed a retrospective observational study to analyse the use of nine frequently prescribed antibiotics and the corresponding antimicrobial resistance rates in hospital acquired E. coli and K. pneumoniae isolates from 18 departments of our institution over 9 years (2008–2016). The main cross-sectional analysis assessed the hypothetical influence of antibiotic consumption on resistance by mixed logistic regression models.

Results

We found an association between antibiotic use and resistance rates in E. coli for amoxicillin-clavulanic acid (OR per each step of 5 defined daily dose/100 bed-days 1.07, 95% CI 1.02–1.12; p = 0.004), piperacillin-tazobactam (OR 2.11, 95% CI 1.45–3.07; p < 0.001), quinolones (OR 1.52, 95% CI 1.25–1.86; p < 0.001) and trimethoprim-sulfamethoxazole (OR 1.59, 95% CI 1.19–2.13; p = 0.002). Additionally, we found a significant association when all nine antibiotics were combined in one analysis. The association between consumption and resistance rates was stronger for nosocomial than for community strains. In K. pneumoniae, we found an association for amoxicillin-clavulanic acid (OR 1.07, 95% CI 1.01–1.14; p = 0.025) and for trimethoprim-sulfamethoxazole (OR 2.02, 95% CI 1.44–2.84; p < 0.001). The combined analysis did not show an association between consumption and resistance (OR 1.06, 95% CI 0.99–1.14; p = 0.07).

Conclusions

We documented an association between antibiotic use and resistance rate for amoxicillin-clavulanic acid, piperacillin-tazobactam, quinolones and trimethoprim-sulfamethoxazole in E. coli and for amoxicillin-clavulanic acid and trimethoprim-sulfamethoxazole in K. pneumoniae across different hospital departments. Our data will support stewardship interventions to optimize antibiotic prescribing at a department level.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0387-0) contains supplementary material, which is available to authorized users.

Temporal association between antibiotic use and resistance in Klebsiella pneumoniae at a tertiary care hospital

Background

β-Lactam/β-lactamase inhibitors (BLBLIs) were introduced into clinical practice as an alternative to carbapenems for treating multi-drug-resistant Klebsiella pneumoniae infections. However, little is known about the relationship between BLBLI treatment and antimicrobial resistance. In this study, we investigated the trends and the temporal association between antibiotic use and antimicrobial resistance in K. pneumoniae isolates obtained between 2012 and 2016.

Methods

Data regarding quarterly consumption (total number of prescriptions per quarter) of all BLBLIs, all third-generation cephalosporins, and all fluoroquinolones at a tertiary care hospital were obtained from the Korean Health Insurance Review and Assessment Service. Susceptibility data (isolation rate of antibiotic resistance per quarter) were obtained from the existing database of the same tertiary hospital. Regression analysis was used to analyze annual trends and cross-correlations to assess the temporal association on a quarterly basis between antibiotic consumption and antibiotic resistance in K. pneumoniae.

Results

The rate of resistance to piperacillin/tazobactam in K. pneumoniae significantly increased over the study period (p < 0.01). The consumption of all BLBLIs was also found to be significantly correlated with the rate of resistance to piperacillin/tazobactam (β = 0.66; p < 0.01), ceftazidime (β = 0.54; p = 0.02), and levofloxacin (β = - 0.60; p = 0.01) with two-quarter lags. Furthermore, the consumption of all third-generation cephalosporins was significantly correlated with rates of K. pneumoniae resistance to ceftazidime (β = 0.64; p < 0.01) with a two-quarter lag and levofloxacin (β = 0.50; p = 0.03) with a quarter lag. The consumption of all fluoroquinolones correlated with resistance rates to ceftazidime (β = 0.14; p < 0.01) with a two-quarter lag.

Conclusions

The rate of resistance to piperacillin/tazobactam in K. pneumoniae increased significantly over the study period and was significantly correlated with BLBLI consumption. While BLBLIs can potentially be utilized as an alternative to carbapenems, our findings reinforce concerns of resistance to these drugs. Further research is needed to understand the implications on resistance of utilizing BLBLIs as a carbapenem-sparing option.

Does ciprofloxacin prophylaxis during chemotherapy induce intestinal microflora resistance to ceftazidime in children with cancer?

To determine the susceptibility and minimal inhibitory concentrations (MIC) of ceftazidime, the commonly used empirical antibiotic in patients with febrile neutropenia, in Escherichia coli and Klebsiella pneumoniae isolated from the intestinal microflora of pediatric patients with cancer, who received ciprofloxacin prophylaxis during chemotherapy, children younger than 18 years with acute lymphoblastic leukemia or lymphoma scheduled to undergo chemotherapy were randomized to receive oral ciprofloxacin 20 mg/kg/day or placebo from the beginning of their chemotherapy. Rectal swab cultures were taken before (R0) and at 1 (R1), 2 (R2), and 3 (R3) weeks during the intervention. The antimicrobial susceptibilities and MICs of ceftazidime and ciprofloxacin were determined via the E test. Of the total 87 patients enrolled, 44 received ciprofloxacin and 43 placebo. A total of 350 isolates were obtained, 62, 49, 46 and 22 from the ciprofloxacin group and 68, 54, 38 and 11 from the placebo group at R0, R1, R2 and R3, respectively. The percentages of ceftazidime susceptibility did not show significantly greater decreases from R0 to R1-R3 in the ciprofloxacin group compared to the placebo group. The MIC₅₀s of ceftazidime showed significantly greater increases after ciprofloxacin prophylaxis during R1-R3 compared to R0 in the intervention group compared to the placebo group (R0, 0.12 vs. 0.12; R1, 0.19 vs. 0.12; R2, 0.19 vs. 0.12 and R3, 0.38 vs. 0.09 μg/mL, respectively). Due to the increasing MIC₅₀ of ceftazidime over time after ciprofloxacin prophylaxis, the use of ceftazidime in patients who have previously had ciprofloxacin prophylaxis needs to be closely monitored.

Intensive care antibiotic consumption and resistance patterns: a cross-correlation analysis

Background

Over recent decades, a dramatic increase in infections caused by multidrug-resistant pathogens has been observed worldwide. The aim of the present study was to investigate the relationship between local resistance bacterial patterns and antibiotic consumption in an intensive care unit in a Romanian university hospital.

Methods

A prospective study was conducted between 1st January 2012 and 31st December 2013. Data covering the consumption of antibacterial drugs and the incidence density for the main resistance phenotypes was collected on a monthly basis, and this data was aggregated quarterly. The relationship between the antibiotic consumption and resistance was investigated using cross-correlation, and four regression models were constructed, using the SPSS version 20.0 (IBM, Chicago, IL) and the R version 3.2.3 packages.

Results

During the period studied, the incidence of combined-resistant and carbapenem-resistant P. aeruginosa strains increased significantly [(gradient = 0.78, R² = 0.707, p = 0.009) (gradient = 0.74, R² = 0.666, p = 0.013) respectively], mirroring the increase in consumption of β-lactam antibiotics with β-lactamase inhibitors (piperacillin/tazobactam) and carbapenems (meropenem) [(gradient = 10.91, R² = 0.698, p = 0.010) and (gradient = 14.63, R² = 0.753, p = 0.005) respectively]. The highest cross-correlation coefficients for zero time lags were found between combined-resistant vs. penicillins consumption and carbapenem-resistant P. aeruginosa strains vs. carbapenems consumption (0.876 and 0.928, respectively). The best model describing the relation between combined-resistant P. aeruginosa strains and penicillins consumption during a given quarter incorporates both the consumption and the incidence of combined-resistant strains in the hospital department during the previous quarter (multiple R² = 0.953, p = 0.017). The best model for explaining the carbapenem resistance of P. aeruginosa strains based on meropenem consumption during a given quarter proved to be the adjusted model which takes into consideration both previous consumption and incidence density of strains during the previous quarter (Multiple R² = 0.921, p = 0.037).

Conclusions

The cross-correlation coefficients and the fitted regression models provide additional evidence that resistance during the a given quarter depends not only on the consumption of antibacterial chemotherapeutic drugs in both that quarter and the previous one, but also on the incidence of resistant strains circulating during the previous quarter.

Electronic supplementary material

The online version of this article (10.1186/s12941-017-0251-8) contains supplementary material, which is available to authorized users.

Correlation between antibiotic consumption and resistance of bloodstream bacteria in a University Hospital in North Eastern Italy, 2008-2014

PURPOSE

The spread of multidrug-resistant bacteria is a worrisome problem worldwide. This study investigated the correlation between antibiotic consumption and antimicrobial resistance trends of the most important bacteria causing bacteremia at the University hospital of Trieste, Italy, from 2008 to 2014.

METHODS

Antibiotic consumption (Defined Daily Dose-DDD-per 100 patient/days) and antibiotic resistance (percentage of antibiotic intermediate o resistant isolates) were analyzed independently with linear correlation by year. Potential correlations between antibiotic consumption and bacteria resistance rates were investigated through the Pearson's correlation.

RESULTS

The overall consumption of antibiotic grew from 80 to 97 DDD 100 patient/days (p = 0.005) during the study period. The increased consumption of amoxicillin/clavulanate and piperacillin/tazobactam was associated with the reduction of MRSA rate from 48.5 to 25.9% (p = 0.007 and p = 0.04, respectively). The increased consumption of piperacillin/tazobactam was associated with the reduction of ESBL-positive Enterobacteriaceae rate from 28.9 to 20.9% (p = 0.01). The increased consumption of carbapenems was associated with the increased rate of carbapenem-resistant Acinetobacter baumannii from 0 to 96.4% (p = 0.03). No carbapenem-resistant Enterobacteriaceae isolates were reported. The consumption of vancomycin grew significantly (p = 0.005). A dramatic spread of vancomycin-resistant Enterococcus faecium occurred in 2014. The consumption of fluoroquinolones and extended-spectrum cephalosporins remained stable.

CONCLUSIONS

An antibiotic stewardship program targeted to limit the consumption of extended-spectrum cephalosporins and fluoroquinolones in favor of amoxicillin/clavulanate and piperacillin/tazobactam correlates with a decreasing rate of MRSA and ESBL-positive Enterobacteriaceae. The analysis of correlations between antibiotic consumption and bacterial resistance rates is a useful tool to orient antimicrobial stewardship policies at local level.

Antimicrobial stewardship of Chinese ministry of health reduces multidrug-resistant organism isolates in critically ill patients: a pre-post study from a single center

Background

China’s Ministry of Health (MOH) has established a policy about the antimicrobial stewardship. To date, the effects of this policy on multidrug-resistant organism (MDRO) in critically ill patients are unknown.

Methods

A pre-post study was conducted on intensive care unit (ICU) patients from June 2010 to May 2011 and from June 2012 to May 2013. Bacterial cultures were conducted at ICU admission and discharge. In June 2011, our hospital started to administer the antimicrobial stewardship program of Chinese MOH. We collected the data on antimicrobial consumption during the 3-year period in all hospital and individual department every month, and analyzed the correlation between the proportion of critically patients colonized or infected with MDRO and antimicrobial consumption.

Results

A total of 978 patients were involved in the present study. With the intervention, the monthly mean Defined Daily Dose (DDD) per 100 occupied bed-days throughout the hospital decreased from 96 ± 7 to 65 ± 6 (p < 0.001), and the proportion of patients colonized or infected with MDRO decreased from 36 to 13% at the time of ICU admission and declined from 48 to 29% at the time of ICU discharge (both p < 0.001). There was a significant positive relationship between the proportion of all critically ill patients colonized or infected with MDRO at ICU admission and the DDD of the entire hospital (R² = 0.7858, p < 0.001).

Conclusion

The antimicrobial stewardship program of Chinese MOH reduced the consumption of antibiotics. Moreover, the proportion of patients colonized or infected with MDRO decreased along with reduced consumption of antibiotics.

Trial registration

Retrospectively registered: NCT02128399; Date of registration: 22 APR 2014; Detail information web link: https://clinicaltrials.gov/ct2/show/NCT02128399?term=NCT02128399&rank=1

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2051-8) contains supplementary material, which is available to authorized users.

Health care associated infections, antibiotic resistance and clinical outcome: A surveillance study from Sanandaj, Iran

AIM: To study the antibiotic susceptibility patterns of gram-negative healthcare associated bacterial infections at two tertiary hospitals in the Sanandaj city, Kurdistan Province, Iran.

METHODS: From January 2012 to December 2012, all positive cultures from potentially sterile body fluids were gathered. They sent to professor Alborzi clinical microbiology center in Shiraz for further analysis and susceptibility testing. The antibiotic susceptibility was determined using the Kirby-Bauer method (disk diffusion technique). The Results were interpreted according to Clinical and Laboratory Standards Institute guidelines against a series of antimicrobials. World Health Organization definitions for Healthcare associated infections were followed.

RESULTS: Seven hundred and thirty-two positive cultures were reported from both hospitals. Seventy-nine isolates/patients fulfilled the study criteria for health-care associated gram-negative infections. The most frequent bacterial cultures were from the pediatric wards (52%). Serratia marcescens (S. marcescens) (38%) Escherichia coli (E. coli) (19%), Klebsiella pneumoniae (K. pneumoniae) (19%), Acinetobacter baumannii (6%), Enterobacter species (6%), Serratia odorifera (4%) and Pseudomonas species (5%) were the most frequently isolated organisms. The susceptibility pattern of common isolates i.e., S. marcescens, E. coli and K. pneumoniae for commonly used antibiotics were as follows: Ampicillin 3.3%, 6.7%, 20%; gentamicin 73.3%, 73.3%, 46.7%; ceftazidim 80%, 73.3%, 33.3%; cefepim 80%, 86.7%, 46.7%; piperacillin/tazobactam 90%, 66.7%, 86.7%; ciprofloxacin 100%, 73.3%, 86.7%; imipenem 100%, 100%, 100%, respectively.

CONCLUSION: The most effective antibiotics against gram-negative healthcare associated infections are imipenem followed by ciprofloxacin. The resistance rate is high against ampicillin and cephalothin. The high mortality rate (46.1%) associated with S. marcescens is alarming.

Systematic review of antibiotic consumption in acute care hospitals

Antibiotic consumption is an easily quantifiable performance measure in hospitals and might be used for monitoring. We conducted a review of published studies and online surveillance reports reporting on antibiotic consumption in acute care hospitals between the years 1997 and 2013. A pooled estimate of antibiotic consumption was calculated using a random effects meta-analysis of rates with 95% confidence intervals. Heterogeneity was assessed through subgroup analysis and metaregression. Eighty studies, comprising data from 3130 hospitals, met the inclusion criteria. The pooled rate of hospital-wide consumption was 586 (95% confidence interval 540 to 632) defined daily doses (DDD)/1000 hospital days (HD) for all antibacterials. However, consumption rates were highly heterogeneous. Antibacterial consumption was highest in intensive care units, at 1563 DDD/1000 HD (95% confidence interval 1472 to 1653). Hospital-wide antibacterial consumption was higher in Western Europe and in medium-sized, private and university-affiliated hospitals. The methods of data collection were significantly associated with consumption rates, including data sources, dispensing vs. purchase vs. usage data, counting admission and discharge days and inclusion of low-consumption departments. Heterogeneity remained in all subgroup analyses. Major heterogeneity currently precludes defining acceptable antibiotic consumption ranges in acute care hospitals. Guidelines on antibiotic consumption reporting that will account for case mix and a minimal set of hospital characteristics recommending standardized methods for monitoring and reporting are needed.

The Relationship between Extensively Drug-Resistant Tuberculosis and Multidrug-Resistant Gram-Negative Bacilli

OBJECTIVE

The relationship between extensively drug-resistant tuberculosis (XDR-TB) and multidrug-resistant Gram-negative bacilli (MDR-GNB) is unclear. Identification of the relationship between XDR-TB and MDR-GNB would have important implications for patient care.

METHODS

We conducted a retrospective study reviewing the records of patients admitted with a confirmed pulmonary TB from 2011 to 2014. To identify the relationship between XDR-TB and MDR-GNB, univariable comparison and multivariable logistic regression were performed.

RESULTS

Among 2962 pulmonary TB patients, 45(1.5%) patients had a diagnosis of XDR-TB. A total of 165 MDR-GNB strains were detected in 143 (4.8%) pulmonary TB patients. XDR-TB patients had a significantly higher occurrence of MDR-GNB than non-XDR-TB patients (24.4% vs. 4.5%; P<0.001). Age (OR 1.02, 95% CI 1.01-1.03), hypoalbuminemia (OR 1.48, 95% CI 1.18-1.85), chronic renal failure (OR 6.67, 95% CI 1.42-31.47), chronic hepatic insufficiency (OR 1.99, 95% CI 1.15-3.43), presence of XDR-TB (OR 6.56, 95% CI 1.61-26.69), and duration of TB diagnostic delay (OR 1.01, 95% CI 1.00-1.02) were the independent risk factors for MDR-GNB infection.

CONCLUSIONS

Patients with XDR-TB have a significantly higher risk of being affected by MDR-GNB pathogen. The underlying mechanism association warrant further studies.

Effects of various antimicrobial stewardship programs on antimicrobial usage and resistance among common gram-negative bacilli causing health care-associated infections: A multicenter comparison

BACKGROUND

The effects of various antimicrobial stewardship programs (ASPs) on both antibiotic consumption and resistance among different hospitals within the same insurance system have rarely been investigated.

METHODS

This 6-year retrospective study included three medical centers with similar facilities and infection control measures in Taiwan. These hospitals used different types of ASPs: one had a hospital-wide preauthorization requirement by infectious diseases physicians for all broad-spectrum antibiotics, covering all intensive care units; the second used the same program, but excluded all intensive care units; and the third used postprescription review only. The nonsusceptibility of unduplicated isolates of gram-negative bacilli causing health care-associated infections and consumption of broad-spectrum antibiotics were analyzed.

RESULTS

Overall, the usage of broad-spectrum antibiotics of all classes escalated significantly over time in all three hospitals, but consumption was lowest under the hospital-wide preauthorization program. Under this ASP, despite a 2-fold increase in the total broad-spectrum antibiotic consumption during study period, some declining trends of resistance were found, including ciprofloxacin-resistant Pseudomonas aeruginosa and Acinetobacter baumannii, and carbapenem-resistant P. aeruginosa. By contrast, the other two hospitals with preauthorization program excluding all intensive care units and postprescription review had similar high broad-spectrum antibiotic consumption, comparable growing trends of resistant strains in general, and the correlations of antibiotic consumption and resistance were basically positive. Carbapenem-resistant A. baumannii increased significantly over time in all three hospitals.

CONCLUSION

This interhospital comparison suggested that hospital-wide preauthorization program is the most effective to reduce key gram-negative bacilli resistance, with the exception of carbapenem-resistant A. baumannii.

Amoxicillin plus temocillin as an alternative empiric therapy for the treatment of severe hospital-acquired pneumonia: results from a retrospective audit

A formulary decision was made at a large provider of acute hospital services in Surrey to replace piperacillin/tazobactam with amoxicillin+temocillin for the empiric treatment of severe hospital-acquired pneumonia. This decision was made because the use of broad-spectrum-β-lactam antibiotics is a known risk factor for Clostridium difficile infection (CDI) and for the selection of resistance. After the antibiotic formulary was changed, a retrospective audit was conducted to assess the effect of this change. Data from patients hospitalised between January 2011 and July 2012 for severe hospital-acquired pneumonia and treated empirically with piperacillin/tazobactam or amoxicillin+temocillin were reviewed retrospectively. Clinical characteristics of patients, data related to the episode of pneumonia, clinical success and incidence of significant diarrhoea and CDI were analysed. One hundred ninety-two episodes of severe hospital-acquired pneumonia in 188 patients were identified from hospital records. Ninety-eight patients received piperacillin/tazobactam and 94 amoxicillin+temocillin. At baseline, the two treatment groups were comparable, except that more patients with renal insufficiency were treated with piperacillin/tazobactam. Clinical success was comparable (80 versus 82 %; P = 0.86), but differences were observed between piperacillin/tazobactam and amoxicillin+temocillin for the rates of significant diarrhoea (34 versus 4 %, respectively; P < 0.0001) and for CDI (7 versus 0 %, respectively; P < 0.0028). This preliminary study suggests that the combination amoxicillin+temocillin is a viable alternative to piperacillin/tazobactam for the treatment of severe hospital-acquired pneumonia. This combination appears to be associated with fewer gastrointestinal adverse events. Further studies are needed to evaluate the place of amoxicillin+temocillin as empiric treatment of severe hospital-acquired pneumonia.

Carbapenem susceptibility among Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae isolates obtained from patients in intensive care units in Taiwan in 2005, 2007, and 2009

To investigate the evolutionary trends in non-susceptibility of carbapenems against the isolates of Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae from patients hospitalized in intensive care units (ICUs) of major teaching hospitals throughout Taiwan during 2005-2009, we applied the breakpoints of MICs recommended by Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing in 2013. Escalations in imipenem MIC levels for overall E. coli and E. cloacae isolates and extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae isolates were noted during this period. The overall MIC levels against imipenem and meropenem for subgroups of ESBL producers of 3 Enterobacteriaceae species were significantly higher than those of respective overall groups in 2007 and 2009. Compared with meropenem, we found that significant evidence of imipenem MIC creep and evidence of extraordinarily high rates of non-susceptibility to ertapenem among isolates of 3 species in 2009 existed. The prominent rises in rates of ertapenem non-susceptibility for ESBL-producing E. coli and K. pneumoniae during 2005-2009 and rate of ESBL positivity for E. cloacae between 4 years were notably found. Based on our findings, ertapenem should be used cautiously in management of the ICU infections caused by these potentially ESBL-producing Enterobacteriaceae isolates in Taiwan.

High burden of antimicrobial drug resistance in Asia

The rapid development of antimicrobial resistance among micro-organisms is a serious public health concern. Moreover, the dissemination of antibiotic-resistant bacteria makes this issue a global problem, and Asia is no exception. For example, since New Delhi metallo-β-lactamase (NDM)-producing Enterobacteriaceae were identified in India, further spread of NDM has become a worldwide threat. However, the epidemiology of antibiotic-resistant bacteria in Asia may be different to other regions, and clinical condition may be worse than in western countries. Antibiotic-resistant bacteria, including community-acquired and hospital-acquired meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-intermediate S. aureus (VISA), vancomycin-resistant enterococci, macrolide- and penicillin-resistant Streptococcus pneumoniae, extend-spectrum β-lactamase (ESBL)-producing Escherichia coli and Klebsiella pneumoniae, carbapenem-resistant Enterobacteriaceae, and multidrug-resistant Pseudomonas aeruginosa and Acinetobacter spp., are becoming prevalent in many countries in Asia. Moreover, the prevalence of each antibiotic-resistant bacterium in each country is not identical. This review provides useful information regarding the critical condition of antibiotic resistance in Asia and emphasises the importance of continuous surveillance of resistance data.

Correlation between antibiotic consumption and carbapenem-resistant Acinetobacter baumannii causing health care-associated infections at a hospital from 2005 to 2010

BACKGROUND/PURPOSE

This study investigated the correlation between antibiotic consumption and the incidence of health care-associated infections (HCAIs) caused by imipenem-resistant Acinetobacter baumannii (IRAB) at a hospital in Taiwan from 2005 to 2010.

METHODS

Data on annual consumption (defined daily dose per 1000 patient-days) of extended-spectrum cephalosporins, β-lactam-β-lactamase inhibitor combinations, carbapenems, aminoglycosides, and fluoroquinolones from 2005 to 2010 were analyzed. Yearly aggregated data on the number of nonduplicate clinical IRAB isolates causing HCAI were collected. The incidence rates of HCAI caused by IRAB were defined as the number of patients infected with IRAB per 1000 inpatient-days.

RESULTS

The trend of total consumption (defined daily dose per 1000 patient-days) of extended-spectrum cephalosporins, carbapenems, and fluoroquinolones was significantly increased, but the use of aminoglycosides decreased during 2005 to 2010. During the same period, the incidence of HCAI caused by IRAB gradually increased. The consumptions of carbapenems and fluoroquinolones were positively correlated with the incidence of HCAI caused by IRAB. There was no significant association between the use of extended-spectrum cephalosporins, β-lactam-β-lactamase inhibitor combinations, and aminoglycosides and the incidence of HCAI caused by IRAB.

CONCLUSION

The increasing use of carbapenems and fluoroquinolones was associated with the increasing incidence of HCAI caused by IRAB.

Carbapenem-resistant Pseudomonas aeruginosa in Taiwan: Prevalence, risk factors, and impact on outcome of infections

BACKGROUND

The prevalence and clinical impact on mortality of carbapenem-resistant Pseudomonas aeruginosa (CRPA) is unclear in Taiwan. We aim to clarify these clinical issues by using data from the Taiwan Surveillance of Antimicrobial Resistance (TSAR) program.

METHODS

Patients from five hospitals with their P. aeruginosa isolates collected by TSAR II-VII (2000-2010) program were considered as the potential study population. All patients with CRPA were enrolled as case patients. Patients with carbapenem-susceptible P. aeruginosa were randomly selected in a 1:1 ratio to case patients as control patients. CRPA isolates were tested for the presence of carbapenemase-producing genes. The clinical data were collected to identify risk factors for CRPA carriage and mortality of P. aeruginosa infection.

RESULTS

The overall prevalence of CRPA was 10.2% (349/3408), which increased significantly by the TSAR period (p = 0.007). Among the 164 enrolled patients, the risk factor for carrying CRPA was previous fluoroquinolone exposure (p = 0.004). The risk factors for mortality among 80 patients with infection by P. aeruginosa included: intensive care unit (ICU) setting, receipt of antifungal therapy, and presence of invasive devices (p = 0.001, 0.010, and 0.017; respectively). Carbapenem resistance did not play a role. Among the 82 CRPA isolates enrolled in this study, 15 isolates were found to carry carbapenemase-producing genes.

CONCLUSION

In Taiwan, the prevalence of CRPA and carriage of carbapenemase-producing genes was high. However, carbapenem resistance did not play a role in the mortality of patients with P. aeruginosa infections.

Impact of an antimicrobial stewardship program with multidisciplinary cooperation in a community public teaching hospital in Taiwan

BACKGROUND

Reports of antimicrobial stewardship programs (ASPs) in community hospitals are limited, with the major focus on specific agents, small settings, or short time periods. Here we present the outcomes of cost control, consumption restraint, and quality of care after a 3-year multidisciplinary ASP in a 415-bed community public teaching hospital.

METHODS

Three strategies for improving antimicrobial stewardship were implemented: education, clinical pharmacists-based intervention, and regular outcome announcement. The steering panel of the program was a committee composed of infection specialists, attending physicians, clinical pharmacists, nurses, and medical laboratorists.

RESULTS

Semiannual data from July 2009 to June 2012 was analyzed. Antibiotic costs declined from $21,464 to $12,146 per 1,000 patient-days (-43.4%). Approximately $2.5 million was saved in 3 years, and estimated labor cost was $3,935 per month. Defined daily dose per 1,000 patient-days were diminished from 906.7 to 717.5 (-20.9%). Significant reductions were found in the consumption of aminoglycosides, first-generation cephalosporins, and aminopenicillins. However, through comprehensive auditing, increasing consumption of fourth-generation cephalosporins and fluoroquinolones was noticed. No significant difference in the quality of care (ie, length of stay, incidence of health care associated infections, and mortality) was observed.

CONCLUSIONS

The multidisciplinary ASP was beneficial to reduce antibiotic cost and consumption. The strategies were practical and worthy to be recommended to community health care settings.

Clustering of antimicrobial resistance outbreaks across bacterial species in the intensive care unit

BACKGROUND

There are frequent reports of intensive care unit (ICU) outbreaks due to transmission of particular antibiotic-resistant bacteria. Less is known about the burden of outbreaks of resistance due to horizontal transfer of mobile genetic elements between species. Moreover, the potential of existing statistical software as a preliminary means for detecting such events has never been assessed. This study uses a software package to determine the burden of species and resistance outbreaks in 2 adjacent ICUs and to look for evidence of clustering of resistance outbreaks consistent with interspecies transmission of resistance elements.

METHODS

A retrospective analysis of data from 2 adjacent 15-bed adult ICUs between 2002 and 2009 was undertaken. Detection of bacterial species-groups and resistance outbreaks was conducted using SaTScan and WHONet-SaTScan software. Resampling and permutation methods were applied to investigate temporal clustering of outbreaks.

RESULTS

Outbreaks occurred for 69% of bacterial species-groups (18/26), and resistance outbreaks were detected against 63% of antibiotics (10/16). Resistance outbreaks against 7 of 10 antibiotics were observed in multiple species-groups simultaneously and there was evidence of inter-species-group dependence for 4 of 7 antibiotics; background temporal changes in resistance did not explain the temporal aggregation of outbreaks in 3 of 7 antibiotics.

CONCLUSIONS

Species outbreaks occurred for the majority of bacteria commonly identified in the ICU. There was evidence for frequent temporal clustering of resistance outbreaks consistent with interspecies transmission of resistance elements. Wider application of outbreak detection software combined with targeted sequencing of bacterial genomes is needed to understand the contribution of interspecies gene transfer to resistance emergence.